Various types of devices operate using radioactive gas or other gas within a gas cell. For example, micro-fabricated atomic clocks (MFACs) and micro-fabricated atomic magnetometers (MFAMs) often include a cavity containing a metal vapor and a buffer gas. In some devices, the metal vapor and the buffer gas are created by dissociating cesium azide (CsN3) into cesium vapor and nitrogen gas (N2).